The Great Wall of... Rock?!

Question

Hypothesis

We think that the rock wall will keep the ground from getting saturated. We think this'll happen because it will block the water and ground. ;D

Materials

Big rocks that stack

Stream table

Sand

Water

Cups w/ a hole

Ruler

Wooden angles

Setup

First, we had to compact the clay/sand. Then, we had to make sure that the ground was stable enough to add the wall. After we checked the ground, Kase, Ava, and Dylan got rocks while Bella made sure the rocks didn't fall. Once the rocks were in a complete "dam", we collected the excess clay/sand. Finally, Bella and Ava got the stream table ready for Mrs. Caruthers. The pictures below are the pictures that Mrs. Caruthers took before we started it all...

Afterwards...

Once we poured the water, the rock wall held for a minute, then one side spewed water and tinsy bits of clay. The rocks that spewed water fell forward a bit. Where the water was poured from the cup, a tiny pool of water formed. After a minute or so, the water was soaked into the clay/sand.

C.E.R

Our hypothesis was half-correct half-not. It was half-correct because a lot of the water fell into the bowl. It was half-not correct because some of the water soaked into the solution. This type of erosion happened because there were gaps in the wall so small that they allowed small particles of water to pass through. There wasn't enough clay/sand past the rocks for a lot of erosion to happen, but some of the rocks collapsed from the side. We needed stronger, bigger, rocks to hold still and keep ALL of the clay/sand from coming through the rock wall.